Art of manufacturing piston-rings.



D. J. CAMPBELL.

ART OF MANUFACTURING PISTON RINGS.

APPLICATION FILED MAR. 7, 1912.

Patented Jan. 14, 1913.

after/M211 noaoioa mnrnn rir rarnnr orrion.

DONALD J. CAMPBELL-F MUsKnGon, MICHIGAN.

ART OF MANUFACTURING PISTON-RINGS.

Specification of Letters Patent.

Patented Jan. 141., 1913.

Application filed March 7, 1912. Serial No. 682,304..

To all whom 2'25 may concern:

Be it known that I, DONALD J. CAMrBnLL, a citizen of the United States of America residing at Muskegon, in the county of Muskegon and State of Michigan, have 1n-. vented certain new and useful Improvements in the Art of Manufacturing Piston- Rings; and I do hereby declare the following to be a full, clear, and exact descrip- 10. tion of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in the art of manufacturing piston rings and ring at one side whereby the ring can be compressed into a less circumference or diameter and inserted in the cylinder, and by its resilience to yieldably engage the inner surface of the cylinder. This compressing of a normally circular ring distorts the same from a true circle and results in an imperfect fit in the c linder. In attempting to obviate this di culty it has also been tried to make the ring with its inner surface eccentric to its outer surface, the removed portion being taken from the thinnest part of the ring whereby the ring when compressed remains more nearly circular. This however, is not entirelysucce'ssful and is also objectionable for the reason that the plane opposite surfaces of the ring are greater at one side than at the other whereby it wears unneven and also leaves a clearance between the thin side of the ring and the bottom of the channel of the piston in which the ringis held.

My invention consists essentially of a novel'method of manufacturing rings consisting of making a ring pattern of substantially the dimensionsof the ring to be produced with the usual allowance for shrinkage and finishing and preferably concentric within and without; inserting in one side of this pattern a segment of substantially the extent of the portion of the ring to be removed to provide for resilience and compression, of the same casting from this modified pattern; removing a portion of the casting substantially corresponding with the segment inserted in the pattern; compress- .ing the casting to close the opening formed therein and while so compressed finishing the ring as preferred, as will more fully appear by reference to the accompanying drawings in which:

Figure l is a plan view of thepattern before being modified; Fig. 2 the-same of the pattern cut through at one side without removing any material portion thereof and expanded to the desired extent the Q broken lines illustrating the change of form Fig. 3 the same with the segment inserted Fig. 4a plan view of a casting made from the modified attern; Fig. 5 a plan view of the casting with the portion removed corresponding to the se ment inserted in the attorn; and Fig. 6 t e casting compresse to close the opening after the Sald1pQIIi/l0n has been removed. 1 n

Like numbers refer to like parts in all of the figures.

l represents a plan of the original pattern; 2 the opening therein after the same .has been severed and expanded to receive the segment; 3' the segment inserted in the pattern; 4 represents a casting made'from said pattern; 5 represents the opening formed therein by removal of a ortion corresponding to the inserted portlon 3 in the pattern, which opening in Fig. 6 is shown same extent that the pattern was expanded. It will be noted that when the pattern is severed at one .side and expanded to receive the-segment itis thrown out of a true.

closed by compressing thejcasting to the tern. It is also obvious that when one side of this distorted casting is removed corresponding to the portion represented in the pattern by the inserted segment that the remainder of the ring will be normally distorted to the same extent as the original pattern was and the casting will obviously berestored in a true circle when compressed to the same extent that the pattern was expanded andthus be a. perfect fit within the cylinder, it being understood that material having uniform resilience throughout is used in the pattern and the casting the distortion of the pattern before casting being neutralized b the restoration of the casting to the condition of the pattern before being distorted by insertion of the segment.

No very smooth finish being necessary upon the inner surface of the ring I find a satisfactory fit of the ring tothe bottom of the groove in the piston is had by leaving the ring unfinished on the inner surface. Leaving the skin of the casting improves the resilience and strength of the ring. The remaining surfaces are finished in the usual manner while the casting is compressed as above described.

What I claim is:

1. The art of making piston ringsand the like, comprising inserting a segment in a circular pattern whereby the pattern is distorted from a true circular form, casting from said pattern, removing from said casting a portion substantially corresponding to the inserted segment in the pattern, compressing the casting to close the opening therein, and finishing the casting to the Working condition,

2. The art of making piston rings and the like, comprising forming a pattern to the Working size and shape of the proposed rin with only shrinkage and finishing materlal added; inserting a segment in said pattern to expand and distort the pattern out of a true circular form, casting from said pattern a ring distorted to correspond to the distortion of the pattern; removing from the casting a portion substantially corresponding to the segment inserted inthe pattern, compressing the casting to close the opening1 formed by said removal'and to remove t e distortion therefrom, and finishing the ring to the Working size and shape While thus compressed.

In testimony whereof I aihx my signature in presence of two witnesses.

DONALD J. CAMPBELL.

Witnesses:

HAROLD U. VAN Anrwnrr, LUTHER V Monnron.

size While in the said compressed 

